This invention is related generally to devices for reflecting electromagnetic energy and, more particularly, to an improved device wherein a reflecting agent is distributed throughout and supported by a solidified foam mass to form the reflecting device.
The size and strength of military installations and equipment present at staging areas or during various operations can be determined by modern day electromagnetic sensing equipment. Such equipment includes radar and devices for sensing electromagnetic energy in the infrared and visual regions of the electromagnetic spectrum. Due to electronic miniaturization, such equipment can be placed on board airplanes or indeed orbited about the earth in satellites.
To maintain an element of secrecy and surprise as well as misleading an enemy force which might be observing military installations and operations, it is desirable to confuse or deceive the enemy force monitoring the sensing equipment. Deception can be performed by active electronic equipment which defeats proper operation of the observing equipment or by passive counter-measures to change the energy reflected back to the equipment. Common examples of passive counter-measures include chaff and decoys for radar equipment.
When decoys are utilized, they simulate buildings, gun emplacements, missile sites or other military equipment, such as tanks, trucks, aircraft and the like. Decoys can be constructed to resemble the particular object simulated and then covered with electrically conductive material so that the radar reflective characteristics of the object simulated are accurately reproduced by the decoy. Alternately, a corner reflector can be utilized as a radar decoy. Each of these forms of decoy construction suffers disadvantages. In the case of a physically accurate model which is constructed and then covered with reflective material, conventional construction techniques are quite time consuming and expensive. However, such physically accurate models simulate a particular structure and present quite accurate reflections to a searching radar. Although the construction problems are reduced when a corner reflector is utilized as a decoy, such decoys do not physically resemble the objects to be simulated and the reflections vary with the angle of incidence of the searching radar and, hence, do not accurately represent the objects.
It is, thus, apparent that the need exists for an electromagnetic energy reflective device and a method for constructing that device which permits rapid, inexpensive construction as well as providing an accurate simulation of the electromagnetic reflective characteristics of an object to be represented by the decoy.